Highly selective palladium-catalyzed Stille coupling reaction toward chlorine-containing NIR electroluminescent polymers

Abstract

High selectivity and yield from aryl-aryl coupling reactions between chlorine-containing aromatic bromides and organotin reagents are reported. The variable reaction selectivity between the bromine and chlorine mainly depends on the electronic effects of the aromatic substrates. The reactivity of the chlorine can be completely restrained by employing the optimized Palladium catalysts, which can be used for the preparation of the chlorine-bearing molecules. Then, a series of high molecular weight conjugated copolymers with chlorine on the backbones are straight forward synthesized under Stille condensation reaction. The chlorine-bearing polymers exhibit much lower LUMO, larger Stokes shift and lower selfabsorption comparing with the non-chloride analogue, for the electron affinity and large steric hindrance of chlorine atoms. Efficient NIR emission centre at about 758 nm can be obtained based on the single layer system.

Chlorination strategy on polymer donors toward efficient solar conversions

“…Bulk heterojunction (BHJ) polymer solar cells (PSCs), comprising conjugated polymer as electron donor and fullerene or nonfullrene derivatives as electron acceptor, have been drawing extensive attentions because of their advantages of low cost, large-area solution processability, light weight, mechanical flexibility and the great potential for commercial applications [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] . Especially the nonfullerence polymer solar cells have shown a new direction for photovoltaic study due to the rapid development in PCE [21][22][23][24] .…”

Fluorination and chlorination effects on quinoxalineimides as an electron-deficient building block for n-channel organic semiconductors

“…This implies a higher resonance effect of chlorine atoms than uorine atoms in the QI system. 43 As a consequence, the electron-withdrawing ability increases in the following order: QI-2Cl > QI-2F > QI-1F > QI-2H. These results reveal that uorination or chlorination on the QI core is quite effective in tuning the LUMO and HOMO levels without considerable steric effects.…”

Ultra‐Sensitive Detection of Proteins Using Chemically Modified Nanoporous PVDF Membrane with Attenuated Near IR Autofluorescence

“…This leads to diffusion of electrons may be possible through the polymer chain or even between chains and gets trapped. For the linear unordered PVDF chains with ABAB arrangement of –CH 2 ‐CF 2 ‐, a wide distribution of trap depths and diffusion lengths may be assumed that the electron has to overcome before recombination . We did not perform any characterization of the traps, as it might divert our objective of this work.…”